http://nabetani.sakura.ne.jp/hena/ord4tetroid/

tetromino_spec.rb

module Tetoromino
  def self.parse(coordinate)
    before = coordinate.split(',').sort
    mx, my = before.map{|c|c.split(//)}.transpose.map(&:sort).map(&:first)
    coordinate = before.map { |o| "#{o[0].to_i - mx.to_i}#{o[1].to_i - my.to_i}" }.join(',')

    ptn_l = %w[
      00,01,02,12
      00,01,10,20
      00,10,11,12
      01,11,20,21
      02,10,11,12
      00,01,11,21
      00,01,02,10
      00,10,20,21
    ]
    ptn_i = %w[
      00,01,02,03
      00,10,20,30
    ]
    ptn_t = %w[
      00,10,11,20
      01,10,11,12
      01,10,11,21
      00,01,02,11
    ]
    ptn_o = %w[
      00,01,10,11
    ]
    ptn_s = %w[
      00,01,11,12
      01,10,11,20
      01,02,10,11
      00,10,11,21
    ]

    return 'L' if ptn_l.include?(coordinate)
    return 'I' if ptn_i.include?(coordinate)
    return 'T' if ptn_t.include?(coordinate)
    return 'O' if ptn_o.include?(coordinate)
    return 'S' if ptn_s.include?(coordinate)
    '-'
  end
end


require 'minitest/autorun'
require 'minitest/spec'
begin
  require 'turn/autorun'
  Turn.config.format = :outline
rescue LoadError
end

MiniTest::Spec.class_eval do
  def self.shared_examples
    @shared_examples ||= {}
  end
end

module MiniTest::Spec::SharedExamples
  def shared_examples_for(desc, &block)
    MiniTest::Spec.shared_examples[desc] = block
  end
  def it_behaves_like(desc, *args)
    self.instance_eval do
      MiniTest::Spec.shared_examples[desc].call(args)
    end
  end
end
Object.class_eval { include(MiniTest::Spec::SharedExamples) }


shared_examples_for 'parse' do |coordinate, pattern|
  describe "parse" do
    it("#{coordinate}"){ Tetoromino.parse(coordinate).must_equal pattern }
  end
end

describe Tetoromino do
  it_behaves_like "parse", "55,55,55,55", "-"
  it_behaves_like "parse", "07,17,06,05", "L"
  it_behaves_like "parse", "21,41,31,40", "L"
  it_behaves_like "parse", "62,74,73,72", "L"
  it_behaves_like "parse", "84,94,74,75", "L"
  it_behaves_like "parse", "48,49,57,47", "L"
  it_behaves_like "parse", "69,89,79,68", "L"
  it_behaves_like "parse", "90,82,91,92", "L"
  it_behaves_like "parse", "13,23,03,24", "L"
  it_behaves_like "parse", "24,22,25,23", "I"
  it_behaves_like "parse", "51,41,21,31", "I"
  it_behaves_like "parse", "64,63,62,65", "I"
  it_behaves_like "parse", "49,69,59,79", "I"
  it_behaves_like "parse", "12,10,21,11", "T"
  it_behaves_like "parse", "89,99,79,88", "T"
  it_behaves_like "parse", "32,41,43,42", "T"
  it_behaves_like "parse", "27,16,36,26", "T"
  it_behaves_like "parse", "68,57,58,67", "O"
  it_behaves_like "parse", "72,62,61,71", "O"
  it_behaves_like "parse", "25,24,15,14", "O"
  it_behaves_like "parse", "43,54,53,42", "S"
  it_behaves_like "parse", "95,86,76,85", "S"
  it_behaves_like "parse", "72,73,84,83", "S"
  it_behaves_like "parse", "42,33,32,23", "S"
  it_behaves_like "parse", "66,57,67,58", "S"
  it_behaves_like "parse", "63,73,52,62", "S"
  it_behaves_like "parse", "76,68,77,67", "S"
  it_behaves_like "parse", "12,11,22,01", "S"
  it_behaves_like "parse", "05,26,06,25", "-"
  it_behaves_like "parse", "03,11,13,01", "-"
  it_behaves_like "parse", "11,20,00,21", "-"
  it_behaves_like "parse", "84,95,94,86", "-"
  it_behaves_like "parse", "36,56,45,35", "-"
  it_behaves_like "parse", "41,33,32,43", "-"
  it_behaves_like "parse", "75,94,84,95", "-"
  it_behaves_like "parse", "27,39,28,37", "-"
  it_behaves_like "parse", "45,34,54,35", "-"
  it_behaves_like "parse", "24,36,35,26", "-"
  it_behaves_like "parse", "27,27,27,27", "-"
  it_behaves_like "parse", "55,44,44,45", "-"
  it_behaves_like "parse", "70,73,71,71", "-"
  it_behaves_like "parse", "67,37,47,47", "-"
  it_behaves_like "parse", "43,45,41,42", "-"
  it_behaves_like "parse", "87,57,97,67", "-"
  it_behaves_like "parse", "49,45,46,48", "-"
  it_behaves_like "parse", "63,63,52,72", "-"
  it_behaves_like "parse", "84,86,84,95", "-"
  it_behaves_like "parse", "61,60,62,73", "-"
  it_behaves_like "parse", "59,79,69,48", "-"
  it_behaves_like "parse", "55,57,77,75", "-"
end

2012-10-13の Yokohama.rb でやっていたヤツ